Question 31372
the equation is
{{{ .045* 2 * x + .08 * x + (180*10^3 - 3*x)* .06 = 10.4 *10^3}}}
{{{.09*x + .08*x - .18*x + 10.8*10^3 = 10.4*10^3}}}
{{{.17*x - .18*x = -400}}}
{{{-.01*x = -400}}}
{{{x = 40*10^3}}}
the amounts to be invested are
80K @ 4.5%
40K @ 8%
60K @ 6%
check
{{{ .045* 80^10^3 + .08 * 40*10^3 + (180*10^3 - 120*10^3)* .06 = 10.4 *10^3}}}
 3.6K + 3.2K + 3.6K = 10.4K
OK